Boot upper



FIG. 1 is a perspective view of a boot upper, showing my new design;

FIG. 2 is a side elevational view thereof;

FIG. 3 is an opposite side elevational view thereof;

FIG. 4 is a front elevational view thereof;

FIG. 5 is a rear elevational view thereof.

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines in FIGS. 1-7 define bounds of the claimed design or represent portions of the boot that form no part of the claimed design. 

The ornamental design for a boot upper, as shown and described. 